Commutator regulator



Feb. 11, 1941. F. RAMPACHER COMMUTATOR REGULATOR Filed May 2l, 1958 ummm@ ffii@ ,D

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INVENTOR HII 48 a/ Fritz TNESSES: WW1/7 Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE COMMUTATOR REGULATOR Application May Z1, 1938, Serial No. 209,169 In Germany June4, 1937 2 Claims.

This invention relates to a commutator type tap changing equipment for transformers.

In prior tap changing equipments of the commutator type, in which selected points of a transformer winding are connected to respective commutator segments, the current supplied to the the load circuit is lead through a plurality of parallel conneclted resistors so arranged as to prevent short circuits between the several winding l portions. In these prior art systems it has been the common practice to employ complicated arrangements for connecting the several brushes and commutator segments through a plurality of sli p rings to the load circuit conductor. l In accordance with the invention a simplified regulator structure is provided in which each of a plurality of impedance elements are directly supported within the cylindrical wall formed by the commutator segments. Each impedance eleizo ment is connected to an associated brush, the several brushes being carried by a brushholder so as to be spacedly positioned about the commutator. The impedance elements together with the brushes are jointly moved during operation of the S5 regulator from one position to another. The ends of several impedance elements remote from their respective brushes are connected to a common conducting member that is in turn connected to the circuit conductor through a single slip ring. 3:) This construction provides a simple commutator type regulator in which it is unnecessary to provide a large number of slip rings for leading out the separate tap connecting circuits.

The several impedance elements that are con- 5 nected in series, respectively, with their associated brushes may be connected in star circuit relation to a common conducting member to which the secondary circuit conductor is connected by means of a slip ring, The several impedance devices whch are arranged to rotate with the brushes in their movement from one position to another position on the commutator may be connected together cin cascade in such manner that two brushes arev connected to the opposite ends .45 of a single impedance element provided with an intermediate tap, and the tap points on two pairs of such impedance elements are connected to the opposite ends of another impedance element, this arrangement of connections being repeated until io the final impedance element is connected atv its midpoint to the secondary circuit conductor.

The impedance elements employed may be either ohmic resistors or inductive reactances, the latter devices having the advantage of lower wat-ts 55 loss.

My invention will be better understood by reference to the accompanying drawing, in which certain preferred embodiments of the invention are illustrated.

Figure 1 is a diagrammatic View of circuits and 5 apparatus illustrating a tap changing equipment organized in accordance with one embodiment of the invention.

Fig. 2 is a sectional View of the regulating cornmutator assembly unit connected in accordance with the circuits shown in Fig. 1,

Fig. 3 is a sectional View of. a regulating commutator assembly unit also organized in accordance with the circuits of Fig. l in which certain parts have different structural relationships than the embodiment illustrated in Fig. 2, and

Fig. 4 is a diagrammatic view sho-Wing a development of a portion of the commutator together with circuit connections organized in accordance with another embodiment of the invention.

Referring to Fig. 1, an alternating current cir cuit is represented by conductors I and 2 through which current is supplied from a source connected to the conductors at the left of the figure for supplying power at a desired voltage to a load connected to conductors I and 3 at the right of the ligure. A tap changing transformer is provided having a primary or shunt winding 4 connected between supply conductors I and 2 and induc- 30 tively related to a secondary or series winding 5 to the mid-point of which conductor 2 is connected. The voltage between the conductors I and 3 is decreased below the voltage between conductors I and 2 or increased in value above 35 the Voltage between conductors I and 2 in accordance with Whether the connection between conduct-orsA 2` and 3 includes a part of the winding 5 between its midpoint and the end 6 thereof or a part of the Winding 5 between its midpoint and 40 the end I thereof.

The secondary winding 5 is provided with a plurality of tap connections 8 that are connected to associated segments 9 of the commutator I2 and with which a plurality of brushes I3 45 engage, the several brushes being connected to a common conducting member or slip ring I4 through a plurality of impedance elements I5, one of which is provided in series with each of the brushes I3. The slip ring I4 is connected 50 to the conductor 3 through a brush I6.

Referring to Fig. 2, a construction is provided in which the several brushes I3 are shown so mounted upon a brushholder I'I as to be held in their proper spaced relation alongl the commutator surface and engage the inside surface of the cylindrical commutator. The brushholder is provided with a central shaft I8 that may be operated through a gear I9 and worm 22, to move the brushes along the commutator for effecting a variation in the output voltage. It will be noted that in Fig. 2 the several resistor elements I3 are positioned within the commutator and are carried directly by the brushholder, the inner ends thereof being connected to a sleeve of conducting material 23 extending from the slip ring I4 and integral therewith.

The voltage supplied to the conductor 3 is determined by the position of the brushes I3. If the brushholder and brushes are moved in a clockwise direction as viewed in Fig. l, the point of effective connection of the winding 5 to the conductor 3 advances along the winding 5 toward the end 'I and if the brushes are moved in a counterclockwise direction, the point of effective connection varies in the opposite direction or toward the end 6 of the winding 5 until the last only of the brushes I3 is in contact with the last segment 9 connected nearest the end 6 of the winding.

Obviously, contact making relays may be provided, if desired, for controlling the operation of a pilot motor to control the position of the brushes through the worm 22 and gear I9 in a well known manner, if automatic operation of the mechanism is desired.

Referring to Fig. 3 in which the circuit connections are the same as those shown in Fig. 1, it will be noted that the specic arrangement of the parts differs from Fig. 1 essentially in that the brushes I3 are mounted in a brushholder 24, the outer brush supporting arm of which is positioned on the outside of the commutator segments 9 and each of the brushes is individually connected by conductors 25 to their associated impedance elements 26, which are shown as positioned vertically within the space between the commutator 9 and the operating shaft I8 that actuates the brushholder 24. The lower ends of the several impedance elements 26 are connected to a conducting member 21 that, in turn, is connected to a slip ring 28 at the top of the assembly, and which is connected to the conductor 3 through the brush I6. The brushes I3 are moved along the surface of the commutator I2 by the shaft I8 in the same manner as in the arrangement illustrated in Fig. 2.

Referring to Fig. 4, the several impedance elements are connected in cascade instead of in star connection between the Several tap points as in Figs. 1, 2 and 3, In Fig. 4 a portion only of the commutator is shown, this portion being enlarged and shown in development in order to more clearly illustrate the circuit connections. Two commutator segments 9 are shown between which are strips of insulating material 29. Eight brushes 3| to 38, inclusive, are illustrated in engagement with the commutator surface, and are connected each to the left end of eight impedance elements 4I to 48, inclusive, as viewed in the drawing. 'Ihe right ends of these impedance elements, as viewed in the drawing, are connected, respectively, to brushes 5I to 58, inclusive, that also engage the commutator surface. The brushes are preferably arranged in two rows, the width of each brush being so selected that it is somewhat smaller than the width of the insulating strips 29 between the conducting segments 9. The brushes connected to the opposite ends of each of the impedance elements 3I to 38 are displaced about the commutator a distance corresponding to the distance between the centers of adjacent commutator segments 9. Accordingly, the opposite ends of each of the impedance elements 4I to 48 will be connected to adjacent commutator segments except when passing from one segment to another in which as shown at 3| and 5I, the brushes are temporarily in engagement with the insulating strips 29 between the conducting segments. The impedance elements 4I to 48 are each provided with intermediate taps, those leading from impedance elements 4I and 45 being connected to the opposite ends of an impedance element 62, those leading from elements 42 and 46 being connected to the opposite ends of an impedance element 63, those from elements 43 and 4'I being connected to the opposite ends of impedance element 64, and those from elements 44 and 48 being connected to the opposite ends of an impedance element 65. Likewise, the impedance elements 62, 63, 64 and 65 are each provided with taps at the middle points, the tap connections from the elements 62 and 63 being connected to the opposite ends of an impedance element 66 and the taps from the middle points of the elements 64 and 65 being connected to the opposite ends of an impedance element 61. In the same manner taps are provided from the middle points of the impedance elements 66 and 61 to the opposite ends of an impedance element 68, the middle point of which is connected to the secondary conductor 3.

In the cascade arrangement of the several impedance elements in accordance with the circuits shown in Fig. 4, no slip rings are required, the several brushes being arranged to move together along the commutator surface in fixed spaced relation. This arrangement of the brushes and circuits provides a particularly ne degree of regulation since the voltage steps between successive movements of the brushes from one commutator segment to another are small.

Many modifications in the details of the structures and circuits above described will occur to those skilled in the art, and I do not Wish to be limited otherwise than by the scope of the accompanying claims.

I claim as my invention:

1. In a voltage regulating system of the class employing a transformer having a primary winding and a secondary winding provided with a plurality of tap points, the combination with a cylindrical commutator the several conducting segments of which are connected to the several tap points, a plurality of brushes for engaging said commutator, a plurality of impedance elements connected in series respectively with said plurality of brushes, a brushholder for spacedly mounting said brushes in contact with said commutator and movable relatively thereto, the irnpedance elements being connected in cascade in` such manner that at any time pairs of displaced brushes are connected through an impedance, the middle points of pairs of which are connected together through an additional impedance and so on until the middle point of the nal impedance element is connected to a secondary circuit conductor.

2. In a voltage regulator system of the class employing a transformer having a winding provided with a plurality of tap points, the comblnation with a commutator comprising a plurality of closely positioned segments forming a cylindrical wall, the segments of which are conbrushes are connected through an impedance element, the middle points of pairs of which are connected together through an additional impedance and so on until the middle point of the final impedance element is connected to a sec- 5 ondary circuit conductor.

FRITZ RAMPACHER. 

